The present invention relates generally to a container for liquids and relates more specifically to a container in which an air duct is arranged in a handle on the container.
A known problem with containers or cans for liquids is that a xe2x80x9cgurglingxe2x80x9d occurs when the liquid is poured out from the can, since the liquid comes out at an uneven rate. The reason for this is that when the liquid leaves the container, the pressure in the increasing air space inside the container falls. After a certain period, the difference between the pressure inside the container and the atmospheric pressure becomes such that air is suddenly drawn into the container and the flow is temporarily interrupted. The flow then continues and the pressure difference increases until the flow is again interrupted as air is sucked in. This therefore gives rise to the above-mentioned gurgling. The gurgling, apart from hindering the actual emptying procedure, also represents a risk, since the liquid which is poured out can splutter and splash. This is especially true, of course, in respect of hazardous substances, such as where the liquid in question is corrosive or otherwise harmful to health.
A known way of avoiding the above-mentioned problem is to arrange ventilation of the liquid space in the container. This can be achieved in a number of ways, one of which is to configure on the container a handle having a duct running therein, which duct at the one end connects to the liquid space and at the other end adjoins the pouring opening. A pressure equalization is thereby achieved, which essentially eliminates the said gurgling.
For such air ducts to work satisfactorily, they must connect to the pouring opening such that surrounding air is allowed to enter the air duct during the actual emptying procedure. This means that the air duct should extend close to the outlet part of the pouring opening. A problem with such air ducts is however that, for practical reasons, they are then given a configuration which comprises a curve. Examples of such solutions are encountered in patent specifications GB 2 098 572, EP 0 058 624, WO 98/35879 and BE 661164. The reason why a curve comes about is that on standard cans the pouring opening is sealed by means of a threaded cap and that the neck formed by the pouring opening must therefore be provided with external threads. This imposes limits on the ways in which the air duct can connect to the pouring opening. A typical configuration is shown in general representation in FIG. 1, which shows a section through a standard-shaped can.
One problem consists in the fact that liquid collects in the curve in the air duct, which liquid acts in this case as a water trap. The pressure-equalizing function of the air duct is thereby weakened or can even be eliminated.
A proposed solution to this problem is encountered in GB 2 098 572 and EP 0 058 624. In these it is proposed that a connecting duct or draining duct to the liquid space is arranged in the lowest part of the curve. This creates the problem, however, that liquid forces its way up in the duct during emptying, thereby preventing, ventilation. The desired function is consequently not obtained.
Another problem consists in the fact that the emptying procedure in known configurations is not wholly satisfactory. As the container is emptied, it is tilted, whereupon the liquid level rises in the pouring opening. The result is that an air duct which emerges in the pouring opening is blocked by the liquid which is present in the pouring opening during emptying. This leads in turn to the non-achievement of the desired ventilation function and to the continuation of the xe2x80x9cgurglingxe2x80x9d problem, i.e. the rate of emptying of the container remains uneven and hence not as good as might be expected.
The known technical solutions involving a duct which ends close to the neck opening further entail major problems in manufacture. Uneven quality is obtained with, for example, a recast air duct, or problems are obtained in connection with suitable wall thickness for the container. In order to reduce the risk of recasting of the duct, less material is used and over-thin walls are then obtained on the container in general. Conversely, if thicker material is used, the risk of recasting of the air duct is increased.
One object of the present invention is to achieve a container of the type stated in the introduction in which the problem of remaining liquid in the air duct has been solved in a better way than in the prior art and which consequently produces better emptying than in known containers of conventional construction.
Another object of the present invention is to achieve a container which can be made with good repeatability and quality in production.
The invention is based partly on the recognition that a more reliable construction is obtained if a slot or opening is arranged in the air duct at its connection with the pouring opening, whilst at the same time providing drainage of any remaining liquid in the air duct.
According to the invention, a container is thus achieved comprising a chamber, a pouring opening arranged in the upper part of the said chamber and having an essentially vertical longitudinal axis, a handle arranged above the chamber, an air duct arranged in the said handle, which air duct at a first end emerges in the chamber and at a second end emerges in the pouring opening, and a wall arranged in the pouring opening, which wall is placed between a part for liquid which is connected to the said chamber and a part for air in which the second end of the said air duct emerges, which container is characterized by an opening in the said wall arranged in the pouring opening between the part for liquid and the part for air.
Other preferred distinguishing features are defined by the appended sub-claims.